The synthesis of novel nucleosides by the photochemical cyclization of the adducts of enaminotriles and ribose. These nucleosides are being tested as antitumor agents. BIBLIOGRAPHIC REFERENCES: J. P. Ferris and R. W. Trimmer, "Photochemical Rearrangement of Enaminonitriles to Imidazoles. Scope and Mechanism", J. Org. Chem. 41, 19 (1976). J. P. Ferris and R. W. Trimmer, "Mechanistic Studies on the Photochemical Reactions of Isoxazoles", J. Org. Chem. 41, 13 (1976).